All of the previos answers are correct, but Ill like to add something extra.
Back in the day when, when western companies didn't had any presence or subsidiaries in Asia, they would contract another company to do the Japanese or Chinese version. This would sometimes cause the Asian version to have more bugs than the western version.
A good example would be the Japanese PC version of Grand Theft Auto Vice City, which was done by Capcom instead of Rockstar Games. The Western PC release was on May 2003 while the Japanese edition was released a couple of months later, on September 2003.
The Japanese edition, due to being "less polished" than the original western release, has a lot of new bugs that are not present on the Western version and can be abused during speedruns to complete the game even faster. There is a thread on the speedrun.com forums explaining most of them.
Because of this, the Japanese edition is used on most of the categories of GTA Vice City due to being faster, specially on the Any% No SSU category (Script Stack Underflow is a bug that allows you to skip almost all of the game).